Building having a metallic, electrically conductive tube, electrical line positioned in a tube of this type and metallic, electrically conductive tube for this purpose

ABSTRACT

A metal, electrically conductive tube, and electrical lines positioned in the tube for electrically powering a building, is provided. The tube includes tube sections connected by a tubular metal and electrically conductive connection part. The tube sections have end sections facing one another. The connection part extends with its inner surface facing outer surfaces of overlapping sections of the tube sections. The connection of the tube sections is achieved by plastic deformation of the connection part in the overlapping sections. A respective contact is provided between the inner surface and the outer surfaces and ensures the electrically conductive connection between the first end section, the connection part and the second end section via an indentation in the inner surface or the outer surfaces, or via fluidic contact between the outer surfaces and the inner surface.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a divisional application of U.S. application Ser.No. 16/635,779, filed on Jan. 31, 2020, which is a 371 of internationalPCT/EP2018/070685, filed on Jul. 31, 2018, which claims priority to DE10 2017 117 369.2, filed on Aug. 1, 2017, the contents of which areincorporated herein in its entirety.

TECHNICAL FIELD

The invention initially pertains to a building with a metallic,electrically conductive tube, wherein electric lines for the electricalpower supply of the building are installed in the tube.

The invention also pertains to electric lines that are installed in ametallic, electrically conductive tube and serve for the electricalpower supply of a building.

The invention furthermore pertains to a metallic, electricallyconductive tube for the installation of electric lines for theelectrical power supply of a building in the tube.

PRIOR ART

In buildings such as residential or industrial buildings, particularlybuildings with wood construction, it is known to install electric linesin tubes. Metallic, electrically conductive tubes particularly are usedfor this purpose in order to ensure immediate grounding, e.g., in caseof a short circuit. The installation of electric lines in tubes of thistype is also important with respect to diminishing a cause of fires. Theindividual tube sections are metallic and electrically conductive, aswell as connected to one another, such that the tube as a whole iselectrically conductive. In case of a short circuit, electrical currentscan thereby be directly discharged via the tube accommodating theelectric lines.

U.S. Pat. No. 7,563,100 B1 discloses a sliding connection between tubesections and a connection part, wherein the sliding part is fixed withrespect to the tube sections by fixing screws. U.S. Pat. No. 3,838,205 Adiscloses a connection between a connection part and associated tubeends, wherein a pressure ring arranged on the radially outer side of theconnection part is acted upon with a hydraulic force. In this way, pinsprovided in the interposed flexible material are also acted upon suchthat they produce an electrically conductive connection between therespective tube section and the connection part in the compressed state.US 2008/0078880 A1 likewise discloses a sliding connection between afirst and a second tube end, wherein the second tube end is realizedwith a widening in the sense of a connecting sleeve. A flexible,electrically conductive connection part is provided for producing anelectrically conductive connection and contains carbon in order torealize the conductivity. Comparable prior art is ultimately also knownfrom CN 1156914 A.

In this context, it is known to use screw connections between the tubesections. As an example, we refer to the prior art according to U.S.Pat. No. 6,262,369 B1.

SUMMARY OF THE INVENTION

In light of the above-described prior art, an objective of the inventioncan be seen in disclosing a connection design for electric linesinstalled in a tube of a building, as well as for a tube to be used forthis purpose, wherein said connection design is advantageous withrespect to the manufacturing technology and improved with respect to theelectrically conductive connection of the tube sections.

With respect to the tube, this objective is attained with claim 1,wherein it is proposed that the connection of the tube sections isachieved as a result of a compression and plastic deformation of theconnection part in the first and the second overlapping section and ofthe first and the second tube section in the first end section and inthe second end section, in which they adjoin one another directly and ina plastically deformed manner in the compressed state, and that acontact is respectively effective in the first and the secondoverlapping section between the inner surface and the first and thesecond outer surface, with the contact ensuring the electricallyconductive connection between the first end section and the connectionpart and between the connection part and the second end section by anindentation in the inner surface or the first and the second outersurface.

This objective is furthermore attained with respect to the building bythe object of claim 2 and with respect to a tube with electric linesinstalled therein by the object of claim 3.

The proposed design makes it possible to advantageously produce aconnection between the electrically conductive tube sections in order tocreate a tube that as a whole is electrically conductive. The connectionbetween the first tube section and a connection part, as well as betweenthe connection part and a second tube section, is also electricallyconductive and advantageously produced with respect to the manufacturingtechnology by plastic deformation in the region of interacting sectionsof the connection part and the tube sections. The plastic deformationpreferably can be achieved as a result of a compression, e.g. acompression carried out by means of a handheld pressing apparatus. As anexample, we refer to WO 2008/138987 A1 (U.S. Pat. No. 8,056,473 B2) withrespect to such handheld pressing apparatuses.

The plastic deformation not only produces a mechanical connectionbetween the connection part and the two associated tube sections, but atthe same time also the required electrically conductive connection inthat a contact means becomes effective between the connection part andthe associated end section of a tube section during the course of theplastic deformation. The contact means may be a mechanically actingmeans, which buries itself in the facing outer surface and/or innersurface by means of respective indentations or protruding ribs duringthe course of the plastic deformation. The contact means mayadditionally be a fluid, which produces or promotes the electric contactbetween the connection part and the associated tube section.

An oxidation layer particularly may form on the surface of aluminumtubes, in which case the associated connection parts may likewiseconsist of aluminum, wherein an electrical conductivity may beinterrupted by this oxidation layer. During normal contact between thefacing surfaces of the tube and the connection part, the arrangement ofa contact means makes it possible to break through such an oxidationlayer or to prevent its formation or to dissolve a formed oxidationlayer to the extent required for realizing an uninterrupted electricalconductivity of the tube.

The tube sections and/or the connection part may also consist of a steelmaterial, wherein the connection parts may also consist, e.g., of zinc.In this case, the same aspects as those described above with referenceto aluminum apply with respect to possible phenomena or changes of thesematerials, which could potentially impair the electrical conductivity.

In a potential embodiment, the connection part may have a (first)receptacle recess for a sealing ring extending transverse to alongitudinal axis of the connection part and a sealing ring accommodatedtherein. The tube accommodating the electric lines or the tube assembledof tube sections and connection parts does not necessarily have to betight with respect to an internal tightness. An internal overpressuregenerally does not exist. However, it is particularly desirable toprevent an admission of moisture, particularly in the form of water,from outside the tube. The moisture may be produced due to watercondensation, a building water damage or rain water or running water ifsuch a tube is installed on the outside of a building. In this context,the term “rain-tight” particularly is used in the US region, in whichthe use of such tubes with electric lines installed therein ispreferred. The term “fluid-tight” is also used for an installation ofsuch tubes, e.g., in concrete.

The sealing ring accommodated in the receptacle recess particularly actsin a sealing manner between the inner surface of the connection part andthe associated outer surface of the tube section in the plasticallydeformed connected position of the connection part and the associatedtube section. Viewed from outside, the sealing ring preferably isarranged in front of the contact means referred to a potential admissionpath of moisture or water, respectively.

It is furthermore preferred that the connection part may respectivelyhave a (first) receptacle recess with a sealing ring accommodatedtherein in two regions that are spaced apart from one another in thelongitudinal direction and respectively intended for receiving a tubeend. A seal is accordingly produced in a preferred embodiment, inparticular, in the connected position of the connection part with thetwo tube sections. In a potential embodiment, a fluid-tight zone isthereby formed between the two sealing rings with respect to thelongitudinal direction of the connection part.

Viewed from the free end of the connection part, the contact means maytherefore be formed or accommodated in the connection part beyond thesealing ring. According to a preferred embodiment, the contact means mayaccordingly be arranged “in the shadow” of the sealing ring, preferablyin the region that is protected from moisture by the sealing ring.

Viewed from the respective free end of the connection part, theconnection part may also respectively have a contact means beyond thesealing ring in two regions that are spaced apart from one another inthe longitudinal direction. Viewed in the longitudinal direction of theconnection part, both contact means are in such an embodimentaccordingly arranged between the sealing regions and therefore in theregion that is protected from fluid.

A contact means may also be formed by a claw part that is realizedseparately of the connection part and arranged on the inner side of theconnection part. In this way, the claw part can be manufacturedseparately and assigned to the connection part. The claw part may alsoconsist of another material than the connection part, optionally of aharder material. The claw part is suitable and designed for buryingitself in the facing surface of the connection part and/or the tubesection, particularly during the course of the plastic deformation ofthe connection part, and for accordingly producing an at leastapproximately form-fitting connection.

For example, the claw part may have claw projections on two sides thatlie opposite of one another in the radial direction referred to thelongitudinal axis of the connection part. The claw projections pointingradially outward may be suitable for burying themselves in the facinginner surface of the connection part whereas the claw projectionspointing radially inward may preferably be designed for correspondinglyburying themselves in the facing outer surface of the tube section.Accordingly, the electrically conductive connection between connectionpart and tube section is in the connected state additionally orexclusively produced by means of the claw part. This claw part isaccordingly made of an electrically conductive material.

The claw part may also be realized in the form of a flat part that hasan annular shape or the shape of a ring segment, wherein the clawprojections protrude from said flat part, preferably radially outwardand/or radially inward. In an annular design of the claw part, the clawsmay be uniformly arranged over the entire circumference of the clawpart. However, only circumferential sections of a completely annularclaw part may alternatively be provided with protruding claws. With theexception of the claws, the claw part may be realized with a rectangularcross section.

The connection part may optionally have a second receptacle recess forthe claw part. However, the claw part may alternatively also be arrangedin the same receptacle recess, in which the directly associated(upstream) sealing ring is also accommodated.

The contact means may also be formed by an indentation in the innersurface of the connection part. A design similar to a claw part mayaccordingly be provided directly on the connection part and pointradially inward such that it can be engaged with the associated tubesection in the connected position. The indentation in the inner surfaceresults in protruding ribs or claws that can bury themselves in thefacing outer surface of the tube section during the course of thecompression. The ribs may be realized continuously in thecircumferential direction. A plurality of claws may be formed adjacentto one another in the circumferential direction in uniform and orderlyor disorderly distribution.

Such a design with indentations may alternatively or additionally alsobe provided on the outer side of the end sections of the tube sectionsin order to correspondingly interact with the inner surface of theconnection part.

The protruding claws of the claw part or the claw-like projectionsresulting between the indentations, for example in the inner surface ofthe connection part, may extend strictly parallel to the longitudinalaxis of the connection part and accordingly perpendicular to acircumferential line extending concentric to the connection part axis.These optionally rib-like claws or projections may alternatively alsoextend at an acute angle to the aforementioned circumferential line.

If the contact means is formed by indenting the inner surface of theconnection part, the contact means is preferably realized integrallywith the connection part and consists of the same material. Such anintegral design also applies to a potential indentation in the outersurface of the tube section.

In an optional alternative embodiment, the contact means may be anelectrically conductive contact fluid. The contact fluid can beintroduced into the corresponding region immediately before theconnection between the connection part and the tube section is produced.In this respect, a corresponding fluid reservoir also may already beprovided in the stand-by position of the connection part.

The contact means may be realized on the basis of grease, e.g. in theform of a contact grease as it is known, for example, in connection withcompressible cable lugs.

If the contact means is realized on the basis of a fluid, it may alsocontain solid fractions such as soot and/or carbon particles in order toachieve the conductivity or to improve the conductivity.

The connection part may have a cover element, e.g. in the form of aplug-type cap, in order to protect the fluidic contact means before theconnection part is used, wherein said cover element can be removed priorto the use of the connection part and the corresponding insertion of anend section of a tube section.

The connection part may also have a stopping element that is formedbeyond the contact means starting from a free end of the connection partand prevents the insertion of the tube section through the connectionpart. The insertion of the tube section is thereby limited by thestopping element, wherein the abutment on the stopping element ensuresthat the contact means can move into an electrically conductive positionrelative to the associated tube section during the course of the plasticdeformation of the connection part.

The stopping element of the connection part can be used for the firsttube section, as well as for the second tube section. In a potentialembodiment, the stopping element may be formed by a bead that extendsconcentric to the longitudinal axis of the connection part and isdirected radially inward, particularly in the form of a—viewed fromoutside—groove-shaped depression. The stopping element may also beformed by elevations that optionally are uniformly distributed over thecircumference and, for example, directed radially inward, particularlyelevations that have the shape of mushroom heads and are formed bycorrespondingly deforming the wall material of the connection part.

Alternatively or additionally to the stopping element, the connectionpart may also have an indicator element for indicating a completeinsertion of an associated tube section into the connection part. Theindicator element preferably is visible for the user from outside,optionally and preferably also after the connection part and the tubesections have been connected by plastic deformation. The indicatorelement may be respectively realized or arranged in such a way that theindicator element becomes visible or changes its shape and/or colorand/or surface design upon the complete insertion of the associated tubesection. In a preferred embodiment, the corresponding indication is onlyachieved once the associated tube section is completely inserted into aposition that makes it possible to produce a proper connection. Astopping element for the tube section can be eliminated in this case.However, the indicator element may alternatively also be provided inaddition to such a stopping element.

In a potential embodiment, the indicator element consists of a flexiblematerial that is displaced radially outward due to the insertion of thetube section. For example, the flexible material may only be acted uponby a corresponding wall region of the tube section, e.g. the endsection, in such a way that the flexible indicator element is displacedor at least partially displaced radially outward once the tube sectionhas been completely inserted. For example, the flexible material maythereby become visible for the user from outside.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described in greater detail below with reference to theattached drawings that, however, merely show an exemplary embodiment. Acomponent, which is described with reference to one of the exemplaryembodiments and not replaced with a different component in anotherexemplary embodiment, is therefore also described as a potentiallyexisting component in this other exemplary embodiment. In the respectivedrawings:

FIG. 1 schematically shows a building with a tube for accommodating anelectric line;

FIG. 2 shows a perspective detail of a tube with installed electricline;

FIG. 3 shows a longitudinal section through a first embodiment of aconnection part for connecting two tube sections prior to carrying out aconnecting process;

FIG. 4 shows an enlarged detail of the region IV in FIG. 3 ;

FIG. 5 shows an alternative embodiment in the form of an illustrationcorresponding to FIG. 4 ;

FIG. 6 shows an illustration corresponding to FIG. 3 , however, afterthe connecting process has been carried out;

FIG. 7 shows an enlarged detail of the region VII in FIG. 6 ;

FIG. 8 shows another embodiment in the form of an illustrationcorresponding to FIG. 3 ;

FIG. 9 shows the embodiment according to FIG. 8 after the connectingprocesses been carried out;

FIG. 10 shows an enlarged detail of the region X in FIG. 9 ;

FIG. 11 shows a detailed section through another embodiment of aconnection part with an associated cover element;

FIG. 12 shows a detailed section according to FIG. 11 through anotherembodiment with an indicator element;

FIG. 13 shows an illustration corresponding to FIG. 12 , however, afteran associated tube section has been inserted into the connection elementand thereby acted upon the indicator element; and

FIG. 14 shows a longitudinal section through another embodiment of aconnection part in the position, in which it is connected to a tubesection.

DESCRIPTION OF THE EMBODIMENTS

A metallic, electrically conductive tube 1, which consists, e.g., ofaluminum and serves for accommodating and installing an electric line 2for the electrical power supply of a building 3, is initially describedwith reference to FIGS. 1 and 2 . In FIG. 1 , the tube is illustratedexcessively large in relation to the building 3.

The tube 1 is essentially composed of tube sections 5 and 6 that areconnected by means of tubular connection parts 4 in the extensiondirection of the tube 1. The connection part 4 is realized in asleeve-like manner and designed for producing a mechanical connection,but particularly also an electrically conductive connection, with thetube sections 5 and 6 as a result of plastic deformation, particularly acompression.

A first end section 7 of a first tube section 5 that is inserted intothe connection part 4 typically faces a second end section 8 of a secondtube section 6, preferably with the same axial orientation along thelongitudinal axis x defined by the tubular connection part 4.

The tubular connection part 4 shown has an inner surface that pointsradially inward and faces a first outer surface 10 of the first tubesection 5 and a second outer surface 11 of the second tube section 6.

In the inserted state of the tube sections 5 and 6 into the connectionpart 4, e.g. according to the illustration in FIG. 3 , a firstoverlapping section A is formed in the overlapping region between theinner surface 9 and the first outer surface 10 of the first tube section5 and a second overlapping section B is formed in the overlapping regionbetween the inner surface 9 of the connection part 4 and the secondouter surface 11 of the second tube section 6.

The connection part 4 may have a stopping element 12 in order torespectively prevent an insertion of a tube section 5, 6 through theconnection part 4 or to define a predetermined insertion position of atube section 5 or 6 within the connection part 4. This stopping elementmay be formed centrally of the connection part 4 with respect to theextension of the longitudinal axis x as shown, e.g. and preferably as aresult of the formation of a bead 13 that extends circumferentially withrespect to the longitudinal axis x and protrudes radially inward overthe inner surface 9. The bead 13 may be formed as a result of acorresponding deformation of the connection part wall 14.

The free end face of the respective end section 7 or 8 of the respectivetube section 5 or 6 abuts on the bead 13 that protrudes radially inwardsuch that its insertion is limited by the stopping element.

The detail according to FIG. 5 furthermore shows that the bead 13 mayradially protrude from the inner surface 9 by a dimension that is chosenequal to or greater than the wall thickness of the tube section wall 15.An electric line 2 routed through a thusly designed connecting region isprotected from damages by the potentially sharp-edged free outer edge ofthe tube section by the bead 13, which protrudes radially inward overthis free outer edge.

The connection of the tube sections 5 and 6 is achieved as a result ofplastic deformation of the connection part 4 in its first and secondoverlapping sections A and B and of the first and second tube sections 5and 6 in the first and second end regions 7 and 8. This plasticdeformation preferably is achieved, for example, as a result of acompression, e.g. by utilizing a preferably hydraulic pressing apparatuswith correspondingly adapted pressing jaws.

A contact means K respectively becomes effective in the overlappingsection A, as well as in the overlapping section B, during the course ofthe plastic deformation in order to produce or improve the electricalconductivity of the tube 1 as a whole, particularly in the region of thedescribed connection.

The contact means K may be realized in the form of a claw part 16 thatis realized separately of the connection part 4 and arranged on theinner side thereof as illustrated in the exemplary embodiment accordingto FIGS. 3 to 7 . The claw part 16 is made of an electrically conductivematerial, particularly a metallic material such as steel.

The claw part 16 may furthermore be realized in the form of analtogether annular flat part, wherein claw projections 17 that protruderadially outward and radially inward are formed on said flat part. Inthe exemplary embodiment shown, three claw projections 17 extending inthe circumferential direction of the claw part 16 are respectivelyprovided on the radially outer side, as well as on the radially innerside. The claw projections 17 and the claw part 16 preferably arerealized integrally and consist of the same material.

The claw part 16 or the contact means K formed thereby is respectivelyassigned to the overlapping section A and the overlapping section B andlies in a correspondingly positioned groove-like receptacle recess 18,which preferably extends circumferentially referred to the longitudinalaxis x and preferably is only open toward the inner surface 9 of theconnection part 4.

The receptacle recess 18 is formed at a distance from the associatedfree end of the connection part 4 referred to the extension of thelongitudinal axis x.

The connection part 4 furthermore comprises two seals 19 that arerespectively realized, in particular, in the form of a sealing ring of athermoplastic material. Each sealing ring 19 extends transverse andtherefore in the circumferential direction referred to the longitudinalaxis x of the connection part 4 and is respectively associated with aninsertion end of the connection part 4.

Each sealing ring 19 may be arranged in a separate receptacle recess ofthe connection part 4 or, as respectively illustrated, in the receptaclerecess 18 that at the same time also accommodates the contact means K.

Viewed from the facing free end of the connection part 4, the contactmeans K according to the exemplary embodiments illustrated in FIGS. 1 to13 preferably is respectively formed or accommodated in the connectionpart 4 beyond the directly associated sealing ring 19. Viewed in theextension direction of the connection part 4 along the longitudinal axisx, the contact means K for interacting with the tube sections 5 and 6are accordingly arranged in a position, in which they are protected fromfluid ingressing from outside by the sealing rings 19.

In the connected position, the sealing rings 19 respectively act againstthe first outer surface 10 of the first tube section 5 and against thesecond outer surface 11 of the second tube section 6 in a sealingmanner.

During the course of the compression, the wall regions of the connectionpart 4 and of the tube sections 5 and 6, which are acted upon by thepressing tool, are plastically deformed in the overlapping sections Aand B such that a mechanical connection, which preferably can no longerbe separated in a non-destructive manner, is subsequently producedbetween the connection part 4 and the tube sections 5 and 6. After thisplastic deformation, the sealing rings 19 are in a sealing positionbetween the inner surface 9 of the connection part 4 in the region ofthe receptacle recess 18 and the directly facing outer surface 10 or 11of the tube section 5 or 6.

The contact means K, i.e. the claw part 16 according to the firstexemplary embodiment, is simultaneously subjected to a load during sucha plastic deformation in such a way that the claw part 16 buries itselfradially outward in the facing inner surface 9 of the connection part 4and radially inward in the facing first or second outer surface 10, 11of the first or the second tube section 5, 6 with its claw projections17. A potentially existing oxidation layer on the outer surface 10, 11and/or the inner surface 9 in the region of the receptacle recess 18 isovercome as a result of this burying action of the claw projections 17such that the electrical conductivity of the connection is ensured (seeFIG. 7 ).

An indentation is thereby produced in the inner surface 9 and/or thefirst and the second outer surface 10, 11.

According to the second exemplary embodiment illustrated in FIGS. 8 to10 , the contact means K may also be formed by an indentation 20 in theinner surface 9 of the connection part 4. Viewed from a free end of theconnection part 4, this indentation 20 is also formed and arrangedbeyond the directly associated sealing ring 19 and therefore in theshadow of the sealing ring 19.

The indentation 20 may be formed by a groove-like depression thatextends in the inner surface 9 circumferentially referred to thelongitudinal axis x. Viewed in the extension direction of thelongitudinal axis x, a plurality of indentations 20, for example up tofive or ten or fifteen such circumferential indentations 20, may berespectively associated with an overlapping section A or B.

With respect to a longitudinal section through this region according tothe enlarged detail in FIG. 10 , the indentations 20 leave tooth-shapedprojections that bury themselves in the respective facing outer surface10 or 11 of the first or the second tube section 5, 6 during the courseof the plastic deformation resulting from a compression or the like inorder to thereby ensure the electrically conductive connection.

The dimensions of the indentations 20 or also of the claw projections 17of the claw part 16, particularly with respect to their extension in theradial direction, are chosen such that they can approximately burythemselves by up to a third, preferably by up to a sixth or eighth,optionally by only up to a tenth or twentieth, of the thickness of thetube wall 15 viewed in the radial direction.

The contact means K may also be an electrically conductive contact fluid21. The contact fluid may be realized, for example, on the basis ofgrease and optionally contain solid fractions such as soot and/or carbonparticles in order to additionally improve the conductivity.

Such a contact fluid 21 may be arranged in the contact region inaddition to the claw part 16 or the indentation 20.

The contact means K may alternatively also be formed by the contactfluid 21 only. According to the embodiment in FIG. 11 , such a contactfluid 21 may be arranged in a correspondingly designed separate (second)receptacle recess 22. This receptacle recess 22 is with respect to thefree end of the connection part 4 formed beyond the directly associatedsealing ring 19 and the receptacle recess 18 accommodating this sealingring 19.

A plug-like cover element 23, which penetrates into the interior fromthe free end of the connection part 4, is provided prior to the use ofthe connection part 4 and protects the contact fluid 21 accommodated inthe receptacle recess 22 from drying out and/or escaping.

Once the cover element 23 has been removed and an associated tubesection 5 or 6 has been inserted, the receptacle opening 22 with thecontact fluid 21 contained therein is exposed radially inward in orderto contact the facing outer surface 10, 11, particularly after thecompression has been carried out.

According to the illustration in FIG. 14 , the contact means K may alsobe the outer edge 24 on the free end of the connection part 4, whereinsaid outer edge 24 at the same time defines the associated receptaclerecess 18 for the sealing ring 19. The outer edge 24 points radiallyinward and is pressed into the respective facing outer surface 10 or 11of the respective tube section 5 or 6 during the course of the plasticdeformation for producing the connection, particularly such that theouter edge 24 at least partially buries itself in the tube wall 15.

The connection part 4 may have an indicator element 25 alternatively oradditionally to a stopping element 12. According to the exampleillustrated in FIGS. 12 and 13 , this indicator element may be realizedin the form of an element that consists of a flexible material, e.g. arubber material.

The indicator element 25 is respectively arranged on or in theconnection part 4 in such a way that it can serve for indicating aproperly inserted tube section 5, 6.

For example, the indicator element 25 may be arranged in an opening 26in the wall 14 of the connection part as shown such that it fills outthis opening completely and preferably in a sealing manner.

In the embodiment shown, the indicator element 25 is in the no-loadstate according to the illustration in FIG. 12 realized such that itbulges radially inward beyond the inner surface 9 of the connection part4. The bulge points radially inward and manifests itself radiallyoutward such that it is visible for the user in the form of acorresponding depression 28 within the opening 26. Viewed from theassociated free end of the connection part 4, the indicator element 25is arranged beyond the associated sealing ring 19, as well as beyond theassociated contact means K, and accordingly beyond the indentations 20in the illustrations in FIGS. 12 and 13 .

The indicator element 25 is accordingly arranged in a region that liesbehind the sealing means and the contact means referred to the extensiondirection of the tube section 5 or 6 into the connection part 4.

When the respective tube section 5 or 6 is inserted into the connectionpart 4, the corresponding end section 7 or 8 acts upon the bulge 27 ofthe indicator element 25 in the region of the corresponding outersurface 10 or 11 once the predetermined insertion depth is reached suchthat the indicator element 25 is displaced radially outward (see FIG. 13). The originally visible depression 28 is thereby subjected to asignificant change that can be perceived optically, as well ashaptically. The depression 28 is not pronounced as deep as in theno-load position in FIG. 12 , wherein the radial displacement of theindicator element 25 toward the outside can also lead to the indicatorelement 25 being aligned radially outward with the surrounding surfaceof the connection part wall 14 or even protruding over this surroundingsurface, e.g. in a dome-like manner.

In addition to the sleeve shape shown, the connection part 4 may also berealized in accordance with all other conventional tube connectordesigns, e.g. in the form of an arc-shaped connector or in the form of aT-shaped connector, wherein each connecting region for receiving a tubesection preferably is realized in accordance with the above-describedcharacteristics.

The preceding explanations serve for elucidating all inventions that areincluded in this application and respectively enhance the prior artindependently with at least the following combinations ofcharacteristics, wherein two, more or all of these combinations ofcharacteristics may also be combined, namely:

A building, which is characterized in that the tube is composed ofmultiple tube sections, which are connected to one another by means of atubular connection part in an extension direction of the tube, whereinthe connection part is electrically conductive and metallic, wherein afirst tube section of the connected tube sections has a first endsection and a second tube section of the connected tube sections has asecond end section and the first end section and the second end sectionface one another, wherein the first tube section has a first outersurface, the second tube section has a second outer surface and theconnection part has an inner surface, wherein the connection partextends with its inner surface facing the first and the second outersurface and overlapping the first and the second outer surface in afirst and a second overlapping section, wherein the connection of thetube sections 5, 6 is achieved as a result of plastic deformation of theconnection part 4 in the first and the second overlapping section A, Band of the first and the second tube section 5, 6 in the first endsection 7 and in the second end section 8, and wherein a contact means Kis respectively effective in the first and the second overlappingsection A, B between the inner surface 9 and the first and the secondouter surface 10, 11, with said contact means ensuring the electricallyconductive connection between the first end section 7 and the connectionpart 4 and between the connection part 4 and the second end section 8 bymeans of an indentation in the inner surface 9 or the first and thesecond outer surface 10, 11 or by means of fluidic contact between thefirst and the second outer surface 10, 11 and the inner surface 9.

An electric line, which is characterized in that the tube is composed ofmultiple tube sections, which are connected to one another by means of atubular connection part in an extension direction of the tube, whereinthe connection part is electrically conductive and metallic, wherein afirst tube section of the connected tube sections has a first endsection and a second tube section of the connected tube sections has asecond end section and the first end section and the second end sectionface one another, wherein the first tube section has a first outersurface, the second tube section has a second outer surface and theconnection part has an inner surface, wherein the connection partextends with its inner surface facing the first and the second outersurface and overlapping the first and the second outer surface in afirst and a second overlapping section, wherein the connection of thetube sections 5, 6 is achieved as a result of plastic deformation of theconnection part 4 in the first and the second overlapping section A, Band of the first and the second tube section 5, 6 in the first endsection 7 and in the second end section 8, and wherein a contact means Kis respectively effective in the first and the second overlappingsection A, B between the inner surface 9 and the first and the secondouter surface 10, 11, with said contact means ensuring the electricallyconductive connection between the first end section 7 and the connectionpart 4 and between the connection part 4 and the second end section 8 bymeans of an indentation in the inner surface 9 or the first and thesecond outer surface 10, 11 or by means of fluidic contact between thefirst and the second outer surface 10, 11 and the inner surface 9.

A tube, which is characterized in that the tube is composed of multipletube sections, which are connected to one another by means of a tubularconnection part in an extension direction of the tube, wherein theconnection part is electrically conductive and metallic, wherein a firsttube section of the connected tube sections has a first end section anda second tube section of the connected tube sections has a second endsection and the first end section and the second end section face oneanother, wherein the first tube section has a first outer surface, thesecond tube section has a second outer surface and the connection parthas an inner surface, wherein the connection part extends with its innersurface facing the first and the second outer surface and overlappingthe first and the second outer surface in a first and a secondoverlapping section, wherein the connection of the tube sections 5, 6 isachieved as a result of plastic deformation of the connection part 4 inthe first and the second overlapping section A, B and of the first andthe second tube section 5, 6 in the first end section 7 and in thesecond end section 8, and wherein a contact means K is respectivelyeffective in the first and the second overlapping section A, B betweenthe inner surface 9 and the first and the second outer surface 10, 11,with said contact means ensuring the electrically conductive connectionbetween the first end section 7 and the connection part 4 and betweenthe connection part 4 and the second end section 8 by means of anindentation in the inner surface 9 or the first and the second outersurface 10, 11 or by means of fluidic contact between the first and thesecond outer surface 10, 11 and the inner surface 9.

A building, an electric line and a tube, which are characterized in thatthe connection part 4 has a (first) receptacle recess 18 for a sealingring 19 extending transverse to a longitudinal axis x of the connectionpart 4 and a sealing ring 19 accommodated therein.

A building, an electric line and a tube, which are characterized in thatthe connection part 4 respectively has a (first) receptacle recess 18with a sealing ring 19 accommodated therein in two regions that arespaced apart from one another in the longitudinal direction andrespectively intended for receiving a tube end.

A building, an electric line and a tube, which are characterized in thatthe contact means K is formed or accommodated in the connection part 4beyond the sealing ring 19 viewed from the free end of the connectionpart 4.

A building, an electric line and a tube, which are characterized in thatthe connection part 4 respectively has, viewed from the respective freeend of the connection part 4, a contact means K beyond the sealing ring19 in two regions that are spaced apart from one another in thelongitudinal direction.

A building, an electric line and a tube, which are characterized in thatthe contact means K is formed by a claw part 16 that is realizedseparately of the connection part 4 and arranged on the inner side ofthe connection part 4.

A building, an electric line and a tube, which are characterized in thatthe claw part 16 has claw projections 17 on two sides that lie oppositeof one another in the radial direction referred to the longitudinal axisx of the connection part 4.

A building, an electric line and a tube, which are characterized in thatthe claw part 16 is realized in the form of a flat part that has anannular shape or the shape of a ring segment, wherein the clawprojections 17 protrude from said flat part.

A building, an electric line and a tube, which are characterized in thatthe connection part 4 has an (optionally second) receptacle recess 22for the claw part 16.

A building, an electric line and a tube, which are characterized in thatthe claw part 16 lies in the (optionally first) receptacle recess 18together with the sealing ring 19.

A building, an electric line and a tube, which are characterized in thatthe contact means K is formed by an indentation 20 in the inner surface9 of the connection part 4.

A building, an electric line and a tube, which are characterized in thatthe contact means K is realized integrally with the connection part 4and consists of the same material.

A building, an electric line and a tube, which are characterized in thatthe contact means K is realized in the form of an electricallyconductive contact fluid 21.

A building, an electric line and a tube, which are characterized in thatthe contact means K is realized on the basis of grease.

A building, an electric line and a tube, which are characterized in thatthe contact means K contains solid fractions such as soot and/or carbonparticles in order to achieve the conductivity.

A building, an electric line and a tube, which are characterized in thatthe connection part 4 has prior to its use a cover element 23 forprotecting the fluidic contact means 21.

A building, an electric line and a tube, which are characterized in thatthe connection part 4 has a stopping element 12, which is formed beyondthe contact means K starting from a free end of the connection part 4and prevents the insertion of the tube section 5, 6 through theconnection part 4.

A building, an electric line and a tube, which are characterized in thatthe connection part 4 has an indicator element 25 for indicating acomplete insertion of an associated tube section 5, 6 into theconnection part 4.

A building, an electric line and a tube, which are characterized in thatthe indicator element 25 consists of a flexible material that isdisplaced radially outward due to the insertion of the tube section 5,6.

All disclosed characteristics are essential to the invention(individually, but also in combination with one another). The disclosurecontent of the associated/attached priority documents (copy of thepriority application) is hereby fully incorporated into the disclosureof this application, namely also for the purpose of integratingcharacteristics of these documents into claims of the presentapplication. The characteristics of the dependent claims alsocharacterize independent inventive enhancements of the prior art withoutthe characteristics of a claim, to which these dependent claims refer,particularly for submitting divisional applications on the basis ofthese claims. The invention specified in each claim may additionallycomprise one or more of the characteristics cited in the precedingdescription, particularly characteristics that are provided withreference symbols and/or cited in the list of reference symbols. Theinvention also concerns designs, in which individual characteristicscited in the preceding description are not realized, particularly ifthey are obviously dispensable for the respective intended use or can bereplaced with other means that have the same technical effect.

LIST OF REFERENCE SYMBOLS

-   1 Tube-   2 Electric line-   3 Building-   4 Connection part-   5 Tube section-   6 Tube section-   7 End section-   8 End section-   9 Inner surface-   10 First outer surface-   11 Second outer surface-   12 Stopping element-   13 Bead-   14 Connection part wall-   15 Tube section wall-   16 Claw part-   17 Claw projection-   18 Receptacle recess-   19 Sealing ring-   20 Indentation-   21 Contact fluid-   22 Receptacle recess-   23 Cover element-   24 Outer edge-   25 Indicator element-   26 Opening-   27 Protruding bulge-   28 Depression-   x Longitudinal axis-   A Overlapping section-   B Overlapping section-   K Contact means

I claim:
 1. A metallic, electrically conductive tube configured toinstall electric lines for an electrical power supply of a building inthe tube, comprising: an electrically conductive and metallic tubularconnection part having a continuous inner surface, a first plurality ofindentations integrally formed in the inner surface, and a secondplurality of indentations integrally formed in the inner surface, thefirst plurality of indentations being spaced from the second pluralityof indentations; first and second electrically conductive and metallictube sections which are connected to one another by the tubularconnection part in an extension direction of the tube, the first tubesection having first and second opposite ends, a first outer surface,and a first end section at the first end thereof, the second tubesection having first and second opposite ends, a second outer surfaceand a second end section at the second end thereof, the first endsection and the second end section facing one another, wherein the innersurface of the connection part faces and abuts against the first outersurface along a first overlapping section, the inner surface of theconnection part faces and abuts against the second outer surface along asecond overlapping section; the first plurality of indentations of theconnection part being provided in the first overlapping section, whereinan electrically conductive connection between the first end section andthe connection part is provided by compression and plastic deformationof the connection part in the first overlapping section along the firstplurality of indentations and of the first tube section in the first endsection, in which they adjoin one another directly and in a plasticallydeformed manner in a compressed state; and the second plurality ofindentations of the connection part being provided in the secondoverlapping section, wherein an electrically conductive connectionbetween the second end section and the connection part is provided bycompression and plastic deformation of the connection part in the secondoverlapping section along the second plurality of indentations and ofthe second tube section in the second end section, in which they adjoinone another directly and in a plastically deformed manner in acompressed state.
 2. The tube according of claim 1, in combination witha building, wherein electric lines for the electrical power supply ofthe building are installed in the tube.
 3. The tube according to claim1, in combination with electric lines that provide electrical powersupply of a building.
 4. A metallic, electrically conductive tubeconfigured to install electric lines for an electrical power supply of abuilding in the tube, comprising: an electrically conductive andmetallic tubular connection part having an inner surface; first andsecond electrically conductive and metallic tube sections which areconnected to one another by the tubular connection part in an extensiondirection of the tube, the first tube section having first and secondopposite ends, a first outer surface, and a first end section at thefirst end thereof, the second tube section having first and secondopposite ends, a second outer surface and a second end section at thesecond end thereof, the first end section and the second end sectionfacing one another, wherein the inner surface of the connection partfaces the first outer surface and overlaps the first outer surface in afirst overlapping section, the inner surface of the connection partfaces the second outer surface and overlaps the second outer surface ina second overlapping section, the connection part overlaps the first endof the first tube section and overlaps the second end of the second tubesection, wherein connection of the tube sections is provided bycompression and plastic deformation of the connection part in the firstand second overlapping sections and of the first and second tubesections in the first and second end sections, in which they adjoin oneanother directly and in a plastically deformed manner in a compressedstate; a first contact providing an indentation in the inner surfaceand/or in the first outer surface in the first overlapping section toform an electrically conductive connection between the first end sectionand the connection part when in the compressed state; a second contactproviding an indentation in the inner surface and/or the second outersurface in the second overlapping section to form an electricallyconductive connection between the second end section and the connectionpart when in the compressed state; and an electrically conductivecontact fluid between the tubular connection part and the first andsecond tube sections.
 5. The tube according to claim 4, wherein thecontact fluid is formed by grease.
 6. The tube according to claim 4,wherein the contact fluid contains solid fractions such as soot and/orcarbon particles in order to achieve the conductivity.
 7. The tubeaccording to claim 4, wherein prior to connection of the connection partwith the first and second tube sections, the connection part has a coverelement attached thereto for protecting the contact fluid.
 8. The tubeaccording of claim 4, in combination with a building, wherein electriclines for the electrical power supply of the building are installed inthe tube.
 9. The tube according to claim 4, in combination with electriclines that provide electrical power supply of a building.
 10. The tubeaccording to claim 1, wherein each first indentation extendscircumferentially along the inner surface of the connection part, andeach second indentation extends circumferentially along the innersurface of the connection part.